A multiple input multiple output (MIMO) system in a wireless communication system refers to that multidimensional space resources are built by means of multiple antennas and these multidimensional space resources form multiple parallel paths to improve a data transmission rate by transmitting multiplex signals. If a sending end of a signal may know information of a channel from the sending end to a receiving end, the sending end may enhance a signal-to-noise ratio of the channel through a beamforming (BF) technology, so as to improve signal reception performance of the receiving end. Currently there are multiple methods for the sending end to obtain channel information, for example, the receiving end may feed back the channel information to the sending end.
In prior art, the sending end may be a beamformer, and the receiving end may be a beamformee; there is generally only one beamformer, which sends a null data packet (NDP) to the beamformee, and the beamformee estimates a channel between itself and the beamformer according to the NDP and feeds back obtained channel information to the beamformer. With rapid growth of network overall throughput requirements, increasing a throughput from a perspective of multiple sending ends becomes an important trend, namely, there will be multiple beamformers. However, currently there is no channel feedback mechanism supporting a scenario of multiple beamformers.